Technical Field
[0001] This invention relates to an interference control apparatus and method for uplink
access in a wireless communication system. The invention is applicable to, but not
limited to, a communication resource access, particularly for an enhanced uplink of
packet-based data employed in a Universal Terrestrial Radio Access (UTRA) Wideband-CDMA
system, as used in the Universal Mobile Telecommunication Standard (UMTS).
Background of the Invention
[0002] Wireless communication systems, for example cellular telephony or private mobile
radio communication systems, typically provide for radio telecommunication links to
be arranged between a plurality of base transceiver stations (BTSs) and a plurality
of subscriber units, often termed mobile stations (MSs).
[0003] Wireless communication systems are distinguished over fixed communication systems,
such as the public switched telephone network (PSTN), principally in that mobile stations
move among BTS coverage areas, and in doing so encounter varying radio propagation
environments.
[0004] In a wireless communication system, each BTS has associated with it a particular
geographical coverage area (or cell). The coverage area is defined by a particular
range where the BTS can maintain acceptable communications with MSs operating within
its serving cell. Coverage areas for a plurality of BTSs can be aggregated for an
extensive coverage area. An embodiment of the present invention is described with
reference to the Third Generation Partnership Project (3 GPP) defining portions of
the Universal Mobile Telecommunication Standard (UMTS), including the time division
duplex (TD-CDMA) mode of operation. 3GPP standards and technical release relating
to the present invention include 3GPP TR 25.211, TR 25.212, TR 25.213, TR 25.214,
TR 25.215, TR 25.808, TR 25.221, TR 25.222, TR 25.223, TR 25.224, TR 25.225, TS 25.309,
TR25.804, TS 21.101, and TR 21.905 hereby incorporated within this application, in
their entireties by reference. 3GPP documents can be obtained from 3GPP Support Office,
650 Route des Lucioles, Sophia Antipolis, Valbonne, FRANCE, or on the Internet at
www.3gpp.org.
[0005] In UMTS terminology, a BTS is referred to as a Node B, and subscriber equipment (or
mobile stations) are referred to as user equipment (UEs). With the rapid development
of services provided to users in the wireless communication arena, UEs can encompass
many forms of communication devices, from cellular phones or radios, through personal
data accessories (PDAs) and MP-3 players to wireless video units and wireless internet
units.
[0006] In UMTS terminology, the communication link from the Node B to a UE is referred to
as the downlink channel. Conversely, the communication link from a UE to the Node
B is referred to as the uplink channel.
[0007] In such wireless communication systems, methods for simultaneously using available
communication resources exist where such communication resources are shared by a number
of users (mobile stations). These methods are sometimes termed multiple access techniques.
Typically, some communication resources (say communications channels, time-slots,
code sequences, etc) are used for carrying traffic while other channels are used for
transferring control information, such as call paging, between the Node Bs and the
UEs.
[0008] It is worth noting that transport channels exist between the physical layer and the
medium access control (MAC) in the system hierarchy. Transport channels can define
how data is transferred over the radio interface. Logical channels exist between MAC
and the radio link control (RLC)/radio resource control (RRC)layers. Logical channels
define what is transported. Physical channels define what is actually sent over the
radio interface, i.e. between layer 1 entities in a UE and a Node B.
[0009] A number of multiple access techniques exist, whereby a finite communication resource
is divided according to attributes such as: (i) frequency division multiple access
(FDMA) in which one of a plurality of channels at different frequencies is assigned
to a particular mobile station for use during the duration of a call; (ii) time division
multiple access (TDMA) whereby each communication resource, say a frequency channel
used in the communication system, is shared among users by dividing the resource into
a number of distinct time periods (time-slots, frames, etc.); and (iii) code division
multiple access (CDMA) whereby communication is performed by using all of the respective
frequencies, at all of the time periods, and the resource is shared by allocating
each communication a particular code, to differentiate desired signals from undesired
signals.
[0010] Within such multiple access techniques, different duplex (two-way communication)
paths are arranged. Such paths can be arranged in a frequency division duplex (FDD)
configuration, whereby a frequency is dedicated for uplink communication and a second
frequency is dedicated for downlink communication. Alternatively, the paths can be
arranged in a time division duplex (TDD) configuration, whereby a first time period
is dedicated for uplink communication and a second time period is dedicated for downlink
communication on an alternating basis.
[0011] Present day communication systems, both wireless and wire-line, have a requirement
to transfer data between communications units. Data, in this context, includes signaling
information and traffic such as data, video, and audio communication. Such data transfer
needs to be effectively and efficiently provided for, in order to optimize the use
of limited communication resources.
[0012] Recent focus in 3GPP has been on the introduction and development of an "enhanced
uplink" feature to provide fast scheduling and allocation of system resources for
uplink packet-based data, and to serve as a compliment to HSDPA (high-speed downlink
packet access). Within HSDPA (downlink), a scheduling (or downlink resource allocation)
entity is placed in the Node-B network entity (previously scheduling was performed
by a Radio network controller, RNC). The scheduler resides within a new MAC entity
termed the MAC-hs.
[0013] For HSDPA, scheduling is generally distributed among Node-Bs and downlink soft handover
(macro-diversity) is not supported. That is to say that a scheduler exists in each
cell which is largely, or wholly unaware of scheduling decisions made in other cells.
Each scheduler operates independently. Feedback is provided to the scheduler from
the UE in the form of Channel Quality Information (CQI). This information enables
the scheduler to accommodate each users particular C/(N+I) (i.e. carrier to noise
plus interference power ratio) situation. If schedulers in other cells are generating
interference to a UE, this is reflected in the CQI report to the UE's serving cell
scheduler, and link parameters may be adjusted in response by the scheduler to maintain
an acceptable quality or reliability of radio communication between the base station
and the UE. Examples of parameters which may be adjusted in accordance to the UE CQI
feedback include: (i) the data rate; (ii) the transmit power; (iii) the modulation
format (QPSK/16-QAM); and (iv) the degree of FEC coding applied
[0014] An enhanced uplink feature was first implemented for the FDD 3GPP variant. In this
case, a scheduler is placed in the Node-B (inside a so-called MAC-e function). As
a result of the scheduling function being located in the Node-B, scheduling is largely
decentralized. However, because uplink signals from a UE may significantly interfere
with the operation of other cells, some degree of co-ordination is required between
schedulers of different cells.
[0015] Soft handover is also supported for uplink in FDD, and this too requires some control
or feedback to the UE from all base stations actively receiving its transmissions.
This can similarly be thought of as a form of scheduler coordination between cells.
[0016] In reference to Fig. 1a, coordination between cell schedulers has been provided for
the FDD enhanced uplink by means of non-serving cells (i.e. cells 003 and 004 in the
"active set" but which are not the primary controlling cell 002) providing feedback
to the UE 001. The "active set" is defined as the set of cells actively receiving
the uplink transmission from the UE 101. Due to the fact that in FDD WCDMA, uplink
signals from each user interfere with those of other users, the transmission from
UE 101 causes some degree of interference in cells 003 and 004.. There is no explicit
direct, co-ordination between Node-B's of the active set (002, 003, and 004) - the
coordination is effected via the control feedback to the UE.
[0017] Control of the UE transmission power and data rate takes the form of grant commands
sent from multiple cells to the same UE. The UE receives an "absolute" grant from
the serving cell, and may also receive "relative" grants from neighboring cells in
the active set. The absolute grant channel (E-AGCH) 007 is used by the serving cell
scheduler to convey information to the UE about which resources it may use. Uplink
resources are generally thought of in FDD WCDMA as "Rise-over-Thermal" (RoT) resources
wherein an allowable received-interference level threshold is set for the base station
(relative to thermal noise in the receiver) and each user is effectively granted a
fraction of this allowable received interference power. As the allowable RoT set-point
is increased, so the interference level at the base station increases and the harder
it becomes for a UEs signal to be detected. Thus, the consequence of increasing the
RoT is that the coverage area of the cell is reduced. The RoT set-point must therefore
be configured correctly for a given deployment to ensure the desired system coverage
is met.
[0018] If a user is located close to a cell boundary, his uplink transmissions may contribute
significantly to the received interference levels observed in a neighbor cell and
may cause an allowable interference target in that cell to be exceeded. This can reduce
the coverage and degrade the radio communication in that neighbor cell. This is an
undesirable scenario, since decisions made by one scheduler in one cell may have a
detrimental (and sometimes catastrophic) impact on the coverage or throughput in another
cell. Some form of preemptive or reactive action is therefore required to accommodate
for this scenario.
[0019] For the FDD WCDMA enhanced uplink, reactive (rather than preemptive) action is taken.
The reactive action takes the form of the E-RGCH feedback commands 005, 006 from the
neighbor cells 004 and 003, respectively, which can be used by a particular scheduler
to reduce the UE transmit power when the uplink signal is causing excessive interference
in that schedulers' cell.
[0020] Thus, uplink interference coordination can be achieved between schedulers but without
explicit need for direct inter-Node-B communication. This is beneficial since a distributed
scheduling architecture may be retained on the network side (where schedulers do not
need to communicate with each other), and this enables the schedulers to be located
in the Node-B which can facilitate faster scheduling, lower latency and faster response
to retransmissions. When Hybrid ARQ is used (H-ARQ) this is also advantageous since
retransmissions can be combined in a soft buffer in the Node-B, obviating the need
to relay soft information over the Node-B/RNC interface (Iub)
[0021] Uplink soft handover between cell sites is typically not supported for TDD. Nor is
the UE currently required to decode information sent on a downlink from any cell other
than the serving cell. Thus, the FDD solution to control intercell interference levels
throughout the system using E-AGCH from serving cells and E-RGCH from neighboring
cells is not appropriate for TDD enhanced uplink. A requirement for the UE's to listen
to commands from multiple cells could be introduced, enabling the same E-RGCH feedback
scheme to be used. However, this would significantly increase the UE receiver complexity
and for this reason, this is not an attractive solution. In reference to Figure 1b,
UE 011 is in TDD communication 017 with its serving Node-B 012, however the UE 011
uplink also causes interference to neighboring cells served by Node-B's 013 and 014.
Other mechanisms for controlling uplink intercell interference must therefore be sought.
It is again advantageous to find solutions to this problem that can operate within
a distributed scheduling architecture in which a scheduler exists for each cell, or
for each Node-B, that may operate independently of schedulers for other cells. This
is so that the benefits of a distributed architecture can be retained. These advantages
include: (i) faster scheduling; (ii) lower transmission latency; (iii) faster response
to retransmissions: (iv) absence of a need for inter-cell or inter-site communication
interfaces; (v) reduction in network complexity; and (vi) favorable architecture for
hybrid automatic repeat requests, H-ARQ.
WO 2004/043102 and
EP-A-1 447 938 both disclose methods for allocating resources in a wireless communication system.
Summary of the Invention
[0022] Embodiments of the present invention exploit the reciprocity of radio channels in
TDD and FDD wireless communication systems to enable distributed schedulers in an
enhanced uplink system to preemptively control intercell interference levels. Each
cell's base station transmits a downlink reference (or so-called "beacon" signal)
The transmission power of the beacon signal (at the transmitter) is known to the UE,
because it is encoded on the beacon signal (and/or may be a default value). A UE monitors
the received signal strength (received signal code power, "RSCP) of the downlink beacon
signals from one or more base stations (received at the UE). The transmitted and received
beacon signal power levels for the respective base stations (Node-Bs) are used by
the UE to control the amount of inter-cell interference that the UE generates by its
uplink transmissions. In further embodiments, the transmitted and received beacon
signal power levels, or values derived therefrom, are transmitted by the UE to its
serving Node-B (base station), where a transmission parameter scheduling mechanism
is used to grant an uplink transmission parameter grant to the UE, thereby controlling
the intercell interference generated by the UE's uplink transmissions. There is no
need for the UE to receive data content from controlling signals from other (non-serving)
cells, and as such embodiments of the present invention advantageously suit the characteristics
of the current 3GPP TDD architecture and avoid major increases in UE receiver complexity.
Brief Description of the Drawings
[0023]
Fig. 1a illustrates a mobile station in communication with a serving cell and members
of an active set in a FDD wireless communication system.
Fig. 1b illustrates a mobile station in communicating with a serving cell, and interfering
with neighboring cells in a TDD wireless communication system. Note: although soft
handover is not supported within the TDD standard (supporting signaling is not included),
it is conceivable that in other or similar systems one may implement a Node-B and
system which does "listen" for out-of-cell UE signals, to decode these and forward
them up to an RNC or other central point or network entity for combining.
Fig. 2a illustrates uplink conditions for a mobile station in favorable radio propagation
conditions for minimum intercell interference (a "high geometry" situation).
Fig. 2b illustrates uplink conditions for a mobile station in difficult radio propagation
conditions (a "low geometry" situation).
Fig. 3a illustrates downlink conditions for a mobile station in favorable radio propagation
conditions (a "high geometry" situation).
Fig. 3b illustrates downlink conditions for a mobile station in difficult radio propagation
conditions (a "low geometry" situation).
Fig. 4a illustrates a prior art method for fair power scheduling.
Fig. 4b illustrates an embodiment of the invention with geometric power scheduling.
Fig. 5 illustrates communication between MAC-e layers of a UE and a Node-b according
to an embodiment of the invention.
Fig. 6 illustrates the operation of a scheduler according to an embodiment of the
invention.
Fig. 7a illustrates a method of allocating uplink resource grants for UEs by a serving
Node-B according to an embodiment of the invention.
Fig. 7b illustrates a method of allocating uplink resource grants for UEs by a serving
Node-B according to another embodiment of the invention.
Fig. 8 illustrates an embodiment of a method to scale uplink resource grants.
Fig. 9 illustrates a system block diagram describing an embodiment of the invention.
Detailed Description of the Invention
[0024] Unless defined otherwise, all technical and scientific terms used herein have the
same meaning as is commonly understood by one of ordinary skill in the art to which
this invention belongs. All patents, applications, published applications and other
publications referred to herein are incorporated by reference in their entirety. If
a definition set forth in this section is contrary to or otherwise inconsistent with
a definition set forth in applications, published applications and other publications
that are herein incorporated by reference, the definition set forth in this section
prevails over the definition that is incorporated herein by reference.
[0025] As used herein, "a" or "an" means "at least one" or "one or more."
[0026] In reference to Figs. 2a and 2b, a UE 201 is in communication with its serving Node-B
(base station) 202. The uplink signal also arrives at neighboring cell Node-Bs 203
and 204. There exists a signal path gain between each UE (denoted "i") and each Node-B
base station receiver ("j") in the system. The path gain between UE "i" and Node-B
base station receiver "j" is denoted g
ij 207, 205, and 206 for Node-Bs 204, 202, and 203, respectively. A UE close to his
serving Node-B will typically have high path gain (illustrated as bold arrows) to
that cell, and is likely to have low path gain (illustrated as thin arrows) to other
cells. For example path gain 205 in Fig. 2a, is large and so is denoted by a bold
arrow.
[0027] For a given transmission from the i
th UE, the ratio of power received at his serving cell (J) to the sum of the power received
at all other cells is given the term "geometry" (Φ):

[0028] Users with high geometry generally interfere less with neighbor cells than UEs with
low geometry. It would thus be beneficial if the scheduler had knowledge of the geometry
of each UE, since the amount of intercell interference they cause could be predicted
before the scheduling grants are sent to the users with the result that the intercell
interference is managed and controlled.
[0029] Users with high and low geometry are illustrated in Figs. 2a and 2b, for high geometry
and low geometry cases, respectively, where the thickness of the transmission path
arrows represents the path gain (a wider arrow representing higher path gain).
[0030] The geometry of the user can be calculated by the network given the received uplink
signal powers at each of the base stations. However, this requires that the received
signal power measurements for a given UE are collected at that UE's serving Node-B,
requiring the establishment of new communication links between the serving Node-B
and the Node-B's in neighboring cells (recall this is something we are trying to avoid).
[0031] Alternatively, the received power measurements for a given UE could be collected
at some other central point (such as a Radio Network Controller, RNC) and then relayed
back out to the UE's serving Node-B. Unfortunately, this involves transmission delays
of the measurement information within the network, and could mean that the information
is "old" before it can be used by the scheduler. It also adds signaling overhead within
the network.
[0032] An embodiment of the present invention exploits the channel reciprocity for TDD to
avoid the issues discussed above. For TDD, because the downlink and uplink channels
are reciprocal, geometry (or the corresponding path gains
gij)can be measured by the UE using downlink reference, or beacon, signals and can be
signaled to the serving Node-B for use by a scheduling process. Such downlink beacon
signals already exist for 3GPP TDD WCDMA systems. They are transmitted at a fixed
reference power (configured for each cell) once or twice within each radio frame.
They are located in the same timeslot as primary synchronization signals, which enable
the UE to find the location of the beacon timeslot. Thus, it is possible for the UE
to locate in time, the beacon transmissions from various cells (including the serving
cell) and to measure the received signal code power levels (RSCP) of those beacon
transmissions including the serving cell.
[0033] The transmit reference power of the beacon signal is signaled within the beacon transmission
itself in each cell. Thus in reference to Figs. 3a and 3b, the UE 201 can listen to
the beacon transmissions from base stations (e.g. beacon transmissions 205, 206, and
207 from Node-Bs 202, 203, and 204, respectively). Each beacon transmission contains
a reference sequence or pilot signal and measurement by the UE of the strength of
this part of the signal is sufficient to provide the desired RSCP measurement. The
information content carried by neighbor cell beacon signals need not necessarily be
decoded by the UE. The reference transmit power levels

pertinent to each beacon signal are signaled to the UE either within the information
content of the serving cell beacon signal, or alternatively, the UE may decode the
neighboring cell beacon signal information, itself. In either case, for each cell
(j), the UE (i) is then able to calculate the path gain:

[0034] By doing this for each cell, it is clear that the UE can calculate his own geometry
Φ
I in an embodiment via equation [1] and can report this to the network for use by an
uplink scheduling process.
[0035] In other embodiments, similar or related metrics (figures of merit) can be derived,
such as the ratio of the serving cell (J) path gain to the strongest neighbor cell
(K) path gain:

[0036] In other embodiments, when the reference transmit power levels

are equal, and the beacon signals from the multiple cells are transmitted over a
common period of time, the UE can make an approximate estimate to Φ
i of equation [1] by taking the ratio of the RSCP measured for the serving cell, to
the residual non-serving cell power, "ISCP". ISCP is the total intercell interference
plus thermal noise (i.e. sum of non-serving cell received power) measured by the UE.
As mentioned, this approximation assumes that

is the same for all cells in the network and that only beacon signals are transmitted
on the beacon timeslot(s) such that ISCP is approximately equal to the sum of RSCP
j for all j≠J.

[0037] ISCP may be estimated in several known ways, two examples are herein described. In
the first example, a noise-free portion of the serving cell beacon signal is reconstructed
and is subtracted from the composite received signal. The power of the remaining signal
is then measured to provide the required ISCP estimate. In the second example, the
total power "T" of the composite signal (containing the beacon signals from the multiple
cells) is measured, and the power of the serving cell signal (RSCP
J) is separately measured. ISCP is then estimated as T-RSCP
J such that:

where ISCP is the total intercell interference plus thermal noise (i.e. sum of non-serving
cell received power) measured by the UE. Note that this approximation assumes that
P
jref is the same for all cells in the network and that only beacon signals are transmitted
on the beacon timeslot(s) such that ISCP is approximately equal to the sum of RSCP
j for all j≠J.
[0038] In a further embodiment, a UE can report the individual RSCP
j values that it received to the serving Node-B, and the serving Node-B calculates
the geometry or other metric itself, to provide to the scheduling process. Calculating
the geometry, or other metric, at the serving Node-B can offload computation from
the UE, however at the cost of transmitting more data from the UE to the serving Node-B.
[0039] In these cases, the geometry (or approximated version thereof) information is conveyed
to the base station scheduler in the serving Node-B associated with each particular
UE. The scheduler can then preemptively avoid excessive intercell interference by
scheduling the UE such that its transmissions do not arrive in the neighbor cells
with excessive power. In this respect the geometry value of equation [3] is particularly
useful, since the maximum received signal level at any neighbor cell (i.e. the strongest
one) may be directly calculated if the transmit power of the UE (or receive power
in the serving cell) is known. The received power level in all other cells can then
be known to be less than this value, and could be considered to somewhat negligible.
[0040] Scheduling of uplink resources to UEs according to their geometry necessarily means
that the transmission rate per timeslot is reduced for UEs with low geometry and is
increased for users with high geometry. Advantageously, this can be shown to have
further benefits in terms of system capacity. Scheduled resources for uplink are generally
thought of as received C/(N+I) resources, or rise over thermal (RoT) resources. When
users are scheduled an amount of uplink resources in proportion to their geometry,
the overall intercell interference generated for a given total amount of resources
scheduled in each cell is reduced when compared to the situation in which each user
is scheduled an equal fraction of the assigned uplink resources.
[0041] In further embodiments, for either TDD or FDD systems, a UE can autonomously use
a beacon signal RSCP measurement to control its own uplink transmission characteristics,
rather than waiting for commands back from the serving Node-B scheduler. This can
effect a very fast secondary interference control which could advantageously be based
upon more recent path loss measurement information at the UE than that used by the
basestation scheduler when granting the transmission resources. The updated measurements
could then be signaled to the basestation scheduler as described in previous embodiments.
The basestation scheduler may then use these updated measurements on which to base
further scheduling decisions. Embodiments of the present invention can also be used
for FDD wireless communication systems. Although uplink and downlink transmission
frequencies are different for FDD systems, rather than common as in TDD systems, a
downlink transmission path gain can provide a less precise, but usable longerterm
estimate of an uplink transmission path gain between a particular Node-B and UE.
[0042] The difference between fair and geometrically-proportional scheduling is shown pictorially
in Figs. 4a and 4b. In prior art Fig 4a, each user is assigned an equal fraction (406,
405, 404, and 403) of the total allocated receive power for serving cell users. In
the embodiment of the invention as shown in Fig. 4b, the receive power resources are
shared among users according to their geometry (user 1 406 has the highest geometry
and user 4 403 has the lowest geometry). In Figs. 4a and 4b 401 and 402 represent
background levels of thermal noise and intercell interference, respectively.
[0043] When implementing geometrically-proportional scheduling, the scheduler can ensure
that each user creates the same (or a similar) level of intercell interference as
each other user, regardless of the users geometry. This is in contrast to fair scheduling
in which the degree of intercell interference caused by each user is inversely proportional
to the user's geometry. As such, in the case of fair scheduling, the system is often
limited by only a few low-geometry users, and this penalizes the high geometry users.
By sharing out the intercell "cost" of each user more fairly amongst users (as in
the geometrically-proportional case), the system is less compromised by these worst-case
users, and system capacity can be increased.
[0044] In an embodiment of the present invention, a 3GPP TDD enhanced uplink system is considered
in which each UE measures the downlink beacon RSCP from multiple neighboring cells
(possibly using the primary synchronization channels to locate the beacon transmissions).
The UEs also decode the system information contained on one or more of the beacon
signals, and retrieve the beacon reference transmit power for each cell (P
jref). Using this information, the UEs calculate the path gain to the serving cell and
to each neighbor cell (via equation [2]). They then calculate the geometry via equation
[1], or a similar metric based upon estimated path gains, and signal this information
to the MAC-e entity responsible for uplink scheduling at the serving cell Node-B.
The geometry information is pertinent to the uplink even though it is measured on
downlink, due to the reciprocity of the TDD radio channel (the same frequency is used
for uplink and downlink transmissions). This geometry information can also be applied
to FDD systems, except that the uplink and downlink channels can be less correlated
and therefore averaged or filtered downlink received signal power measurement or path
gain would need to be used, adding latency to the interference control response time.
[0045] Without loss of generality the feedback information may be contained or otherwise
multiplexed within an actual enhanced uplink transmission, or may be carried on an
associated control channel. The feedback signaling is communicated between the MAC-e
entity in the UE and the MAC-e entity in the serving cell Node-B as shown in Fig.
5.
[0046] The network (UTRAN) is comprised of Radio Network Controllers (RNCs) each subtending
multiple cell sites (Node-B's). Each Node-B contains a MAC-e entity responsible for
scheduling of one or more cells or sectors supported by the Node-B. The schedulers
do not require coordination between sites, and hence the need for Node-B to Node-B
interfaces is obviated. Of course, schedulers dealing with different cells subtended
by the same Node-B may communicate internally to the Node-B if the implementation
dictates.
[0047] The scheduler is responsible for sharing out uplink interference resources amongst
users. The interference resources consist of an intracell interference component and
an intercell interference component and are specified as allowable interference levels
relative to the thermal noise (so-called "Rise over Thermal", RoT).
[0048] A TDD WCDMA receiver can incorporate a joint detection receiver which can cancel
some of the energy from other serving cell users. However, the cancellation process
is not perfect and some residual interference may remain. The residual interference
from each user is likely to vary to some degree in proportion with the received power
from that user. Thus, a user granted more received power at the base station will
have a higher intracell "cost" than a user granted a lower received-power quotient.
[0049] The scheduler can calculate/estimate an intracell cost factor (F
intra) for each UE (i), which when multipled by the hypothetical received power grant results
in an absolute intracell cost associated with that grant. The cost factor could for
example simply be a fixed scalar related to the efficiency of the joint detection
process (0...1). For example:

[0050] Each user's transmission to the serving cell will also appear at a neighboring cell
receiver at a level corresponding to the granted received power in the serving cell,
and the ratio of the path gain to the serving cell and the path gain to the particular
neighboring cell. Users granted more received power at the serving cell will interfere
more with neighboring cells than those granted less power. Additionally, users with
low geometry will interfere with neighbor cells more than those with high geometry.
[0051] As for the intracell case, the scheduler can determine an overall intercell "cost"
factor associated with a hypothetical grant of received power resources to a given
UE. The cost factor is based upon the geometry of the user. When the cost factor is
multipled by the grant, an absolute intercell cost is obtained. For example:

[0052] Using the notion of intracell and intercell cost, the scheduler can apportion the
allowable intracell and intercell costs to the various UEs in the schedule according
to a fairness criterion.
[0053] For fair scheduling, each scheduled user in the cell governed by a particular scheduler
should receive an equal received-power grant. The sum of the costs of the equal power
grants should not exceed the total allowable intracell or intercell costs (these are
set in order to maintain a particular outage or system reliability/stability).
[0054] For geometrically proportional scheduling, each scheduled user in the cell governed
by a particular scheduler should receive a received-power grant in proportion to his
geometry.
Again, the sum of the costs of the power grants should not exceed the total allowable
intracell or intercell costs.
[0055] Variable degrees of fairness can also be implemented between the fair scheduling
and geometrically proportional scheduling methods, wherein power grants are scaled
by a factor that is the sum of a geometry factor and a constant that represents a
fairness parameter. An embodiment of the scheduling process is illustrated in Fig.
6. By consideration of the users' geometry and the setting of the fairness parameter,
a scheduling scheme is effected which can:
(i) predict the impact of a hypothetical grant to a UE in terms of the level of intercell
interference created; (ii) preemptively control and manage intercell interference
in the system;
(iii) maintain a desired coverage area for cells throughout the network; retain a
distributed scheduling architecture for lower latency, faster retransmissions, and
H-ARQ benefits; (iv) obviate the need for downlink feedback signaling overhead from
other cells to control interference levels; and (v) obviate the need for a UE receiver
to listen and decode messages from multiple cells, hence avoiding an increase in the
UE receiver complexity.
[0056] Fig. 7a is a block diagram exemplifying a process for calculating uplink resource
grants for each UE served, subject to total allowable intercell and intracell cost
constraints according to an embodiment of the invention. In this particular embodiment,
RSCPs are monitored from the serving cell and Node-Bs of neighboring cells by a UE
in step 701. In step 702, the UE transmits the monitored RSCPs to its serving Node-b
for subsequent processing. In step 703, the serving Node-b receives the monitored
RSCPs from the UE and in step 704, uplink path gains between the UE and the serving
and active set Node-bs are estimated on the basis of the respective downlink paths,
owing to the reciprocity of the TDD channel. In step 705, the estimated uplink path
gains are used to calculate a geometry value (or similar figure of merit, as discussed
above) for each UE served. In step 706, intercell and intracell cost factors for each
UE served by a particular Node-b are calculated by the Node-b, for example according
to equations 8 and 9, above.
[0057] Fig. 7b is an alternative embodiment in which uplink path gain estimate calculations
(step 704) and geometry value or similar figure of merit calculations (705) are performed
by the UE rather than the serving Node-B. This can reduce the necessary feedback communication
bandwidth from the UE to the Node-B, but at the cost of additional computation bandwidth,
memory, and power consumption at the UE. It may also mean that less overall information
content is conveyed (for example, information specific to the path gain to each individual
cell may be lost) and so signaling efficiency is traded-off against information content
and scheduling performance.
[0058] Fig. 8 shows an embodiment of step 707 of Figs. 7a and 7b in which all intracell
costs and all intercell costs are separately summed (steps 801 and 801) and compared
to maximum respective cost targets, in step 803. Depending on whether the intracell
total cost is higher or whether the intercell cost is higher the uplink resource grants
are scaled for each served UE by the ratio of total allowable intercell (or intracell,
respectively) cost so that no maximum (intercell or intracell) cost target is exceeded.
This process can be applied iteratively, as necessary. Although as illustrated in
the embodiment of Fig. 7, steps 703 through 707 are executed at a serving Node-b (in
particular by a MACe of serving Node-b), intracell and/or intercell costs could be
estimated by the UE, and transmission parameters adjusted in order that the UE does
not exceed predefined interference targets in serving and/or neighbor cells.
[0059] Figure 9 illustrates a hardware embodiment of a further embodiment of the invention.
UE 908 comprises signal connection means 909 operatively connecting receiver 913,
transmitter, 910, antenna switch or duplexer 914, processor 911, and memory 912 as
is well known in the art of user equipment for wireless communications. Antenna switch
or duplexer 914 is connected with an UE antenna 915 for sending and receiving radio
signals. 901 and 917 are Node-Bs, connected to their respective antennas 906 and 922.
Node-b 901 can be essentially identical to Node-b 917, except that for purposes of
this illustration, Node-b 917 is assumed to be a serving node for UE 908. Block 903
is a transmitter, block 904 is a controller, and block 905 is electronic memory. Block
902 is signal interconnection. Processor 904, under control of a set of computer instructions
stored in memory 905 directs transmitter 903 to transmit RSCPs to UE 908. UE 908 monitors
the reference signal (beacon signal) and measures the corresponding received power
levels ("RSCP") and in one embodiment, relays them to its serving Node-B for subsequent
processing. Received signal power levels can be measured through analog techniques
such as an analog received signal strength indicator (RSSI) circuit, or estimated
by digital signal processing techniques, as is well known in the art. In alternative
embodiments UE 908 can perform additional processing on the RSCP transmissions, and
the results sent to the serving Node-b. Serving Node-b 917. Block 919 in serving Node-b
is a receiver, block 920 is a controller, block 921 is an electronic memory, and block
918 is a signal connection means. Controller 920 of serving Node-b contains within
the electronic memory 921 to calculate uplink resource grants to each served UI according
to at least one of the embodiments, discussed above. Uplink transmission parameters
that can be adjusted by controller 920 to alter intracell and intercell uplink costs
for a UE can include, without limitation: (i) data rate; (ii) transmission power;
(iii) degree and/or nature of forward error correction; (iv) modulation format; and/or
(v) code resource usage. For example, for a given uplink transmission power, data
rate, degree of forward error correction, and modulation format, a first level of
transmission reliability (data error rate) can be achieved. A lowering of the data
rate, or an increase of the amount of forward error correction applied to the system,
or the use of a more robust modulation scheme will result in a second, improved transmission
reliability when transmitted at the same transmission power. Such an improvement may
be exploited by a subsequent lowering of the UE transmission power to once again achieve
the first transmission reliability. In such a way, adjustment of the data rate, or
forward error correction coding, or modulation scheme may be used to adjust the UE
transmission power, thereby controlling intercell interference while still achieving
the required transmission reliability.
[0060] Variations and extensions of the embodiments described are apparent to one of ordinary
skill in the art. For example, the uplink scheduler can calculate the effect or cost
of a hypothetical grant of uplink resources on other cells before making the grant,
using the reported measurements to derive in whole or in part the effect or cost value.
[0061] Other applications, features, and advantages of this invention will be apparent to
one of ordinary skill in the art who studies this invention disclosure. Therefore
the scope of this invention is to be limited only by the following claims.
1. A method for allocating uplink transmission resources in a wireless communication
system, comprising:
receiving (701), by a mobile station (201), a plurality of reference signal transmissions
transmitted at a respective plurality of transmission power levels by a respective
plurality of base stations (202, 203, 204);
measuring, by the mobile station (201), a plurality of received signal power levels
for the respective plurality of reference signal transmissions; and
wherein the method is
characterized by:
calculating, by the mobile station (201), a corresponding at least one first figure
of merit based upon a first relationship of measured, received signal power levels
and respective plurality of transmission power levels;
transmitting the corresponding at least one first figure of merit; and
receiving an allocation of uplink transmission resources in response thereto.
2. The method of claim 1 further comprising calculating, by the mobile station, a second
figure of merit based upon a second relationship of at least two of a first plurality
of figures of merit.
3. The method of claim 1, further comprising decoding, by the mobile station, the plurality
of transmission power levels from the respective plurality of reference signal transmissions.
4. The method of claim 1, further comprising receiving, by the mobile station, the plurality
of transmission power levels from one of the plurality of base stations.
5. A computer-readable medium having computer-executable instructions for performing
a method for allocating uplink transmission resources in a wireless communication
system, comprising:
receiving (701), by a mobile station (201), a plurality of reference signal transmissions
transmitted at a respective plurality of transmission power levels by a respective
plurality of base stations (202, 203, 204);
measuring, by the mobile station (201), a plurality of received signal power levels
for the respective plurality of reference signal transmissions;
wherein the computer-readable medium is
characterized by:
calculating, by the mobile station, a corresponding at least one first figure of merit
based upon a first relationship of measured, received signal power levels and respective
plurality of transmission power levels;
transmitting the corresponding at least one first figure of merit; and
receiving an allocation of uplink transmission resources in response thereto.
6. A mobile station (201) for a wireless communication system, comprising:
means for receiving a plurality of reference signal transmissions transmitted at a
respective plurality of transmission power levels by a respective plurality of base
stations;
means for measuring a plurality of received signal power levels for the respective
plurality of signal code power level transmissions;
wherein the mobile station is
characterized by:
means for calculating a corresponding at least one first figure of merit based upon
a first relationship of the measured, received signal power levels and respective
plurality of transmission power levels;
means for transmitting the corresponding at least one first figure of merit; and
means for receiving an allocation of uplink transmission resources in response thereto.
7. A method for allocating uplink transmission resources in a wireless communication
system, comprising:
receiving (703), by a base station, an uplink data transmission from a mobile station,
indicating receiving, by the mobile station, a plurality of reference signal transmissions
transmitted at a respective plurality of transmission power levels by a respective
plurality of base stations;
receiving, by the base station, a plurality of received signal power levels, measured
by the mobile station, for the respective plurality of reference signal transmissions
received by the mobile station;
wherein the method is
characterized by:
receiving, by the base station a calculation from the mobile station, of a corresponding
at least one first figure of merit (705) based upon a first relationship of the plurality
of the received signal power level measurements and a respective plurality of transmission
power levels; and
granting, by the base station, an allocation of uplink transmission resources in response
thereto.
8. The method of claim 7 further comprising receiving, from the mobile station, a calculation
of a second figure of merit based upon a second relationship of at least two of a
first plurality of figures of merit, wherein granting, by the base station, comprises
granting a parameter for an uplink transmission resource to the mobile station, responsive
to the second relationship.
9. The method of claim 8, wherein an uplink transmission parameter comprises at least
one of (i) data rate, (ii) uplink transmission power, (iii) degree or nature of forward
error correction, (iv) modulation format, or (v) code resource usage.
10. The method of claim 1 or claim 7, wherein the wireless communication system is described
by a Third Generation partnership project Universal Mobile Telecommunication Standard,
the base station is a Node-B, the mobile station is a UE, and the Node-B further comprises
an uplink scheduler for granting uplink transmission parameters to the mobile station
within a MAC-e.
11. The method of claim 7 in which the uplink scheduler estimates an interfering signal
power level to a neighboring cell, of a hypothetical grant of uplink resources before
making an uplink resource grant.
12. A computer-readable medium having computer-executable instructions for performing
a method for allocating uplink transmission resources in a wireless communication
system, comprising:
receiving (703), by a base station, an uplink data transmission from a mobile station,
indicating receiving, by the mobile station, a plurality of reference signal transmissions
transmitted at a respective plurality of transmission power levels by a respective
plurality of base stations;
receiving, by the base station, a plurality of received signal power levels, measured
by the mobile station, for the respective plurality of reference signal transmissions
received by the mobile station; and
wherein the computer-readable medium is
characterized by:
receiving, by the base station a calculation, from the mobile station, of a corresponding
at least one first figure of merit based upon a first relationship of the plurality
of the received signal power level measurements and the respective plurality of transmission
power levels; and
granting, by the base station, an allocation of uplink transmission resources in response
thereto.
13. The computer-readable medium of claim 12 having computer-executable instructions for
performing a method, further comprising: receiving, from the mobile station, a calculation
of a second figure of merit based upon a second relationship of at least two of a
first plurality of figures of merit, wherein granting, by the base station, comprises
granting a parameter for an uplink transmission resource the mobile station, responsive
to the second relationship, wherein an uplink transmission parameter comprises at
least one of (i) data rate, (ii) uplink transmission power, (iii) degree or nature
of forward error correction, (iv) modulation format, or (v) code resource usage.
14. The computer-readable medium of claim 13, wherein the wireless communication system
is described by a Third Generation partnership project Universal Mobile Telecommunication
Standard, the base station is a Node-B, the mobile station is a UE, and the Node-B
further comprises an uplink scheduler for granting a parameter for an uplink transmission
resource to the mobile station within a MAC-e.
15. The computer-readable medium of claim 14, in which the uplink scheduler estimates
an interfering signal power level to a neighboring cell, of a hypothetical grant of
uplink resources before making an uplink resource grant.
16. A base station (202) for a wireless communication system, comprising:
means for receiving an uplink data transmission from a mobile station (201), indicating
receiving, by the mobile station, a plurality of reference signal transmissions transmitted
at a respective plurality of transmission power levels by a respective plurality of
base stations;
means for receiving by the base station, a plurality of received signal power levels,
measured by the mobile station, for the respective plurality of reference signal transmissions
received by the base station; and
wherein the base station is
characterized by:
means for receiving, by the base station, a calculation from the mobile station of
a corresponding at least one first figure of merit based upon a first relationship
of the plurality of the received signal power level measurements and a respective
plurality of transmission power levels; and
means for granting, by the base station, an allocation of uplink transmission resources
in response thereto.
17. A wireless communication system comprising:
means for receiving, by a mobile station, a plurality of reference signal transmissions
transmitted at a respective plurality of transmission power levels by a respective
plurality of base stations;
means for measuring, by the mobile station, a respective plurality of received signal
power levels corresponding to the plurality of reference signal transmissions;
means for transmitting, by the mobile station, information based upon the plurality
of received signal power levels associated with the respective plurality of reference
signal transmissions;
wherein the wireless communication system is
characterized by:
means for receiving, by a base station, an uplink data transmission from the mobile
station, indicating at least one figure of merit derived by the mobile station and
based at least in part upon measurements of received signal power levels for a plurality
of reference signal transmissions from a respective plurality of base stations, as
measured by the mobile station; and
means for granting, by the base station, an uplink transmission resource parameter
to the mobile station, responsive to the at least one figure of merit; and
means for receiving, by the mobile station, the uplink transmission resource parameter
grant.
18. The wireless communication system of claim 17, wherein an uplink transmission resource
parameter comprises at least one of (i) data rate, (ii) uplink transmission power,
(iii) degree or nature of forward error correction, (iv) modulation format, or (v)
code resource usage.
19. The wireless communication system of claim 17, wherein the wireless communication
system is described by a Third Generation partnership project Universal Mobile Telecommunication
Standard, the base station is a Node-B, the mobile station is a UE, and the Node-B
further comprises an uplink scheduler for granting a parameter for an uplink transmission
resource to the mobile station within a MAC-e.
20. The wireless communication system of claim 19, further comprising means by which the
uplink scheduler estimates an interfering signal power level to a neighboring cell,
of a hypothetical grant of uplink resources before making an uplink resource grant.
1. Verfahren zum Zuweisen von Uplink-Übertragungsressourcen in einem drahtlosen Kommunikationssystem,
umfassend:
Empfangen (701) an einer Mobilstation (201) einer Mehrzahl von Bezugssignalübertragungen,
die bei einer entsprechenden Mehrzahl von Sendeleistungspegeln von einer entsprechenden
Mehrzahl von Basisstationen (202, 203, 204) gesendet wurden, und
Messen durch die Mobilstation (201) einer Mehrzahl von empfangenen Signalleistungspegeln
für die jeweilige Mehrzahl der Bezugssignalübertagungen,
wobei das Verfahren
gekennzeichnet ist durch:
Berechnen durch die Mobilstation (201) einer entsprechenden wenigstens einen ersten Leistungszahl
basierend auf einer ersten Beziehung der gemessenen empfangenen Signalleistungspegel
und der jeweiligen Mehrzahl von Sendeleistungspegeln,
Übertragen der entsprechenden wenigstens einen ersten Leistungszahl und
Empfangen einer Zuweisung von Uplink-Übertragungsressourcen als Antwort darauf.
2. Verfahren nach Anspruch 1, ferner umfassend das Berechnen durch die Mobilstation einer
zweiten Leistungszahl basierend auf einer zweiten Beziehung von wenigstens zwei aus
einer ersten Mehrzahl von Leistungszahlen.
3. Verfahren nach Anspruch 1, ferner umfassend das Decodieren durch die Mobilstation
der Mehrzahl von Sendeleistungspegeln der jeweiligen Mehrzahl von Bezugssignalübertagungen.
4. Verfahren nach Anspruch 1, ferner umfassend das Empfangen an der Mobilstation der
Mehrzahl von Sendeleistungspegeln von einer der Mehrzahl der Basisstationen.
5. Computerlesbares Medium mit computerausführbaren Befehlen zum Durchführen eines Verfahrens
zum Zuweisen von Uplink-Übertragungsressourcen in einem drahtlosen Kommunikationssystem,
umfassend:
Empfangen (701) an einer Mobilstation (201) einer Mehrzahl von Bezugssignalübertragungen,
die bei einer entsprechenden Mehrzahl von Sendeleistungspegeln von einer entsprechenden
Mehrzahl von Basisstationen (202, 203, 204) gesendet wurden, und
Messen durch die Mobilstation (201) einer Mehrzahl von empfangenen Signalleistungspegeln
für die jeweilige Mehrzahl der Bezugssignalübertragungen,
wobei das computerlesbare Medium
gekennzeichnet ist durch:
Berechnen durch die Mobilstation (201) einer entsprechenden wenigstens einen ersten Leistungszahl
basierend auf einer ersten Beziehung der gemessenen empfangenen Signalleistungspegel
und der jeweiligen Mehrzahl von Sendeleistungspegeln,
Übertragen der dazugehörigen wenigstens einen ersten Leistungszahl und
Empfangen einer Zuweisung von Uplink-Übertragungsressourcen als Antwort darauf.
6. Mobilstation (201) für ein drahtloses Kommunikationssystem, umfassend:
Mittel zum Empfangen einer Mehrzahl von Bezugssignalübertragungen, die bei einer entsprechenden
Mehrzahl von Sendeleistungspegeln von einer entsprechenden Mehrzahl von Basisstationen
gesendet wurden, und
Mittel zum Messen einer Mehrzahl von empfangenen Signalleistungspegeln für die jeweilige
Mehrzahl der Signalleistungspegel,
wobei die Mobilstation
gekennzeichnet ist durch:
Mittel zum Berechnen einer entsprechenden wenigstens einen ersten Leistungszahl basierend
auf einer ersten Beziehung der gemessenen empfangenen Signalleistungspegel und der
jeweiligen Mehrzahl von Sendeleistungspegeln,
Mittel zum Übertragen der dazugehörigen wenigstens einen ersten Leistungszahl und
Mittel zum Empfangen einer Zuweisung von Uplink-Übertragungsressourcen als Antwort
darauf.
7. Verfahren zum Zuweisen von Uplink-Übertragungsressourcen in einem drahtlosen Kommunikationssystem,
umfassend:
Empfangen (703) an einer Basisstation von einer Uplink-Datenübertragung von einer
Mobilstation, die das Empfangen an der Mobilstation einer Mehrzahl von Bezugssignalübertragungen
anzeigt, die bei einer entsprechenden Mehrzahl von Sendeleistungspegeln von einer
entsprechenden Mehrzahl von Basisstationen gesendet wurden, und
Empfangen an der Basisstation einer Mehrzahl von empfangenen Signalleistungspegeln,
die von der Mobilstation für die jeweilige Mehrzahl der von der Mobilstation empfangenen
Bezugssignalübertagungen gemessen wurden,
wobei das Verfahren
gekennzeichnet ist durch:
Empfangen an der Basisstation einer Berechnung von der Mobilstation einer dazugehörigen
wenigstens einen ersten Leistungszahl (705) basierend auf einer ersten Beziehung der
Mehrzahl der empfangenen Signalleistungspegelmessungen und einer entsprechenden Mehrzahl
von Sendeleistungspegeln und
Erteilen durch die Basisstation einer Zuweisung von Uplink-Übertragungsressourcen als Antwort darauf.
8. Verfahren nach Anspruch 7, ferner umfassend das Empfangen an der Mobilstation einer
Berechnung einer zweiten Leistungszahl basierend auf einer zweiten Beziehung von wenigstens
zwei einer ersten Mehrzahl von Leistungszahlen,
wobei das Erteilen durch die Basisstation das Erteilen eines Parameters für eine Uplink-Übertragungsressource
an die Mobilstation, in Antwort auf die zweite Beziehung umfaßt.
9. Verfahren nach Anspruch 8, wobei ein Uplink-Übertragungsparameter wenigstens eines
von (i) einer Datenrate, (ii) einer Uplink-Übertragungsleistung, (iii) einem Ausmaß
oder einer Art einer Vorwärtsfehlerkorrektur, (iv) einem Modulationsformat oder (v)
einer Coderessourcenbenutzung umfaßt.
10. Verfahren nach Anspruch 1 oder 7, wobei das drahtlose Kommunikationssystem durch einen
Third Generation partnership project Universal Mobile Telecommunication Standard beschrieben
wird, die Basisstation ein B-Knoten ist, die Mobilstation eine Teilnehmereinrichtung
UE ist, und der B-Knoten ferner einen Uplink-Scheduler zur Erteilung von Uplink-Übertragungsparametern
an die Mobilstation in einer e-Medienzugriffssteuerung (MAC-e) umfaßt.
11. Verfahren nach Anspruch 7, in welchem der Uplink-Scheduler einen interferierenden
Signalleistungspegel einer hypothetischen Erteilung von Uplink-Ressourcen auf einer
benachbarten Zelle einschätzt, bevor eine Uplink-Ressourcenerteilung durchgeführt
wird.
12. Computerlesbares Medium mit computerausführbaren Befehlen zum Durchführen eines Verfahrens
zum Zuweisen von Uplink-Übertragungsressourcen in einem drahtlosen Kommunikationssystem,
umfassend:
Empfangen (703) an einer Basisstation einer Uplink-Datenübertragung von einer Mobilstation,
die das Empfangen an der Mobilstation einer Mehrzahl von Bezugssignalübertragungen
anzeigt, die bei einer entsprechenden Mehrzahl von Sendeleistungspegeln von einer
entsprechenden Mehrzahl von Basisstationen gesendet wurden, und
Empfangen an der Basisstation einer Mehrzahl von empfangenen Signalleistungspegeln,
die von der Mobilstation gemessen wurden, für die jeweilige Mehrzahl der von der Mobilstation
emfangenen Bezugssignalübertagungen,
wobei das computerlesbare Medium
gekennzeichnet ist durch:
Empfangen an der Basisstation einer Berechnung von der Mobilstation einer dazugehörigen
wenigstens einen ersten Leistungszahl basierend auf einer ersten Beziehung der Mehrzahl
der empfangenen Signalleistungspegelmessungen und der jeweiligen Mehrzahl von Sendeleistungspegeln
und
Erteilen durch die Basisstation einer Zuweisung von Uplink-Übertragungsressourcen als Antwort darauf.
13. Computerlesbares Medium nach Anspruch 12 mit computerausführbaren Befehlen zum Durchführen
eines Verfahrens, ferner umfassend: Empfangen von der Mobilstation einer Berechnung
von einer zweiten Leistungszahl basierend auf einer zweiten Beziehung von wenigstens
zwei aus einer ersten Mehrzahl von Leistungszahlen, wobei das Erteilen durch die Basisstation
das Erteilen eines Parameters einer Uplink-Übertragungsressource an die Mobilstation
in Antwort auf die zweite Beziehung umfaßt und wobei ein Uplink-Übertragungsparameter
wenigstens eines von (i) einer Datenrate, (ii) einer Uplink-Übertragungsleistung,
(iii) einem Ausmaß oder einer Art einer Vorwärtsfehlerkorrektur, (iv) einem Modulationsformat
oder (v) einer Coderessourcenbenutzung umfaßt.
14. Computerlesbares Medium nach Anspruch 13, wobei das drahtlose Kommunikationssystem
durch einen Third Generation partnership project Universal Mobile Telecommunication
Standard beschrieben wird, die Basisstation ein B-Knoten ist, die Mobilstation eine
Teilnehmereinrichtung UE ist und der B-Knoten ferner einen Uplink-Scheduler zur Erteilung
eines Parameter für eine Uplink-Übertragungsressource an die Mobilstation in einer
e-Medienzugriffssteuerung (MAC-e) umfaßt.
15. Computerlesbares Medium nach Anspruch 14, in welchem der Uplink-Scheduler einen interferierenden
Signalleistungspegel einer hypothetischen Erteilung von Uplink-Ressourcen auf einer
benachbarten Zelle einschätzt, bevor eine Uplink-Ressourcenerteilung durchgeführt
wird.
16. Basisstation (202) für ein drahtloses Kommunikationssystem, umfassend:
Mittel zum Empfangen einer Uplink-Datenübertragung von einer Mobilstation (201), die
das Empfangen an der Mobilstation einer Mehrzahl von Bezugssignalübertragungen anzeigt,
die bei einer entsprechenden Mehrzahl von Sendeleistungspegeln von einer entsprechenden
Mehrzahl von Basisstationen gesendet wurden, und
Mittel zum Empfangen an der Basisstation einer Mehrzahl von empfangenen Signalleistungspegeln,
die von der Mobilstation gemessen wurden, für die jeweilige Mehrzahl der von der Mobilstation
empfangenen Bezugssignalübertagungen,
wobei die Basisstation
gekennzeichnet ist durch:
Mittel zum Empfangen an der Basisstation einer Berechnung von der Mobilstation einer
dazugehörigen wenigstens einen ersten Leistungszahl basierend auf einer ersten Beziehung
der Mehrzahl der empfangenen Signalleistungspegelmessungen und der jeweiligen Mehrzahl
von Sendeleistungspegeln und
Mittel zum Erteilen durch die Basisstation einer Zuweisung von Uplink-Übertragungsressourcen als Antwort darauf.
17. Drahtloses Kommunikationssystem umfassend:
Mittel zum Empfangen an einer Mobilstation einer Mehrzahl von Bezugssignalübertragungen,
die bei einer jeweiligen Mehrzahl von Sendeleistungspegeln von einer jeweiligen Mehrzahl
von Basisstationen gesendet wurden,
Mittel zum Messen durch die Mobilstation einer Mehrzahl von empfangenen Signalleistungspegeln,
die der jeweiligen Mehrzahl der Bezugssignalübertragungen entsprechen,
Mittel zum Übertragen durch die Mobilstation von Informationen basierend auf der Mehrzahl
von empfangenen Signalleistungspegeln zusammen mit der jeweiligen Mehrzahl von Bezugssignalübertragungen,
wobei das drahtlose Kommunikationssytem
gekennzeichnet ist durch:
Mittel zum Empfangen an einer Basisstation einer Uplink-Datenübertragung aus der Mobilstation,
die wenigstens eine von der Mobilstation abgeleitete und wenigstens teilweise auf
Messungen der empfangenen Signalleistungspegel für eine Mehrzahl von Bezugssignalübertragungen
der jeweiligen Mehrzahl von Basisstationen basierende von der Mobilstation gemessene
Leistungszahl anzeigt,
Mittel zum Erteilen durch die Basisstation eines Uplink-Übertragungsressourceparameter an die Mobilstation
in Antwort auf die wenigstens eine Leistungszahl und
Mittel zum Empfangen an der Mobilstation der Erteilung des Uplink-Übertragungsressourceparameters.
18. Drahtloses Kommunikationssystem nach Anspruch 17, wobei ein Uplink-Übertragungsparameter
wenigstens eines von (i) einer Datenrate, (ii) einer Uplink-Übertragungsleistung,
(iii) einem Ausmaß oder einer Art einer Vorwärtsfehlerkorrektur, (iv) einem Modulationsformat
oder (v) einer Coderessourcenbenutzung umfaßt.
19. Drahtloses Kommunikationssystem nach Anspruch 17, wobei das drahtlose Kommunikationssystem
durch einen Third Generation partnership project Universal Mobile Telecommunication
Standard beschrieben wird, die Basisstation ein B-Knoten ist, die Mobilstation eine
Teilnehmereinrichtung UE ist, und der B-Knoten ferner einen Uplink-Scheduler zur Erteilung
eines Parameter für eine Uplink-Übertragungsressource an der Mobilstation in einer
e-Medienzugriffssteuerung (MAC-e) umfaßt.
20. Drahtloses Kommunikationssystem nach Anspruch 19, ferner umfassend Mittel mit welchen
der Uplink-Scheduler einen interferierenden Signalleistungspegel einer hypothetischen
Erteilung von Uplink-Ressourcen auf einer benachbarten Zelle einschätzt, bevor eine
Uplink-Ressourcenerteilung durchgeführt wird.
1. Procédé d'allocation de ressources de transmission de liaison montante dans un système
de communication sans fil, comprenant :
la réception (701), par une station mobile (201), d'une pluralité de transmissions
de signaux de référence transmis à une pluralité respective de niveaux de puissance
de transmission par une pluralité respective de stations de base (202, 203, 204) ;
la mesure, par la station mobile (201), d'une pluralité de niveaux de puissance de
signaux reçus pour la pluralité respective de transmissions de signaux de référence
; et
dans lequel le procédé est
caractérisé par :
le calcul, par la station mobile (201) d'au moins un premier facteur de mérite correspondant
basé sur une première relation de niveaux de puissance de signaux reçus mesurés et
une pluralité respective de niveaux de puissance de transmission ;
la transmission de l'au moins un premier facteur de mérite correspondant ; et
la réception d'une allocation de ressources de transmission de liaison montante en
réponse à celle-ci.
2. Procédé selon la revendication 1, comprenant en outre le calcul, par la station mobile,
d'un deuxième facteur de mérite basé sur une deuxième relation d'au moins deux facteurs
d'une première pluralité de facteurs de mérite.
3. Procédé selon la revendication 1, comprenant en outre le décodage, par la station
mobile, de la pluralité de niveaux de puissance de transmission de la pluralité respective
de transmissions de signaux de référence.
4. Procédé selon la revendication 1, comprenant en outre la réception, par la station
mobile, de la pluralité de niveaux de puissance de transmission par une station de
la pluralité de stations de base.
5. Support lisible par ordinateur comportant des instructions exécutables par ordinateur
pour exécuter un procédé d'allocation de ressources de transmission de liaison montante
dans un système de communication sans fil, comprenant :
la réception (701), par une station mobile (201), d'une pluralité de transmissions
de signaux de référence transmis à une pluralité respective de niveaux de puissance
de transmission par une pluralité respective de stations de base (202, 203, 204) ;
la mesure, par la station mobile (201), d'une pluralité de niveaux de puissance de
signaux reçus pour la pluralité respective de transmissions de signaux de référence
;
dans lequel le support lisible par ordinateur est
caractérisé par :
le calcul, par la station mobile, d'au moins un premier facteur de mérite correspondant
basé sur une première relation de niveaux de puissance de signaux reçus mesurés et
une pluralité respective de niveaux de puissance de transmission ;
la transmission de l'au moins un premier facteur de mérite correspondant ; et
la réception d'une allocation de ressources de transmission de liaison montante en
réponse à celle-ci.
6. Station mobile (201) pour un système de communication sans fil, comprenant :
un moyen pour recevoir une pluralité de transmissions de signaux de référence transmis
à une pluralité respective de niveaux de puissance de transmission par une pluralité
respective de stations de base ;
un moyen pour mesurer une pluralité de niveaux de puissance de signaux reçus pour
la pluralité respective de transmissions de niveaux de puissance de code de signal
;
dans lequel la station mobile est
caractérisée par :
un moyen pour calculer au moins un premier facteur de mérite correspondant basé sur
une première relation de niveaux de puissance de signaux reçus mesurés et une pluralité
respective de niveaux de puissance de transmission ;
un moyen pour transmettre l'au moins un premier facteur de mérite correspondant ;
et
un moyen pour recevoir une allocation de ressources de transmission de liaison montante
en réponse à celle-ci.
7. Procédé d'allocation de ressources de transmission de liaison montante dans un système
de communication sans fil, comprenant :
la réception (703), par une station de base, d'une transmission de données de liaison
montante depuis une station mobile, indiquant la réception, par la station mobile,
d'une pluralité de transmissions de signaux de référence transmis à une pluralité
respective de niveaux de puissance de transmission par une pluralité respective de
stations de base ;
la réception, par la station de base, d'une pluralité de niveaux de puissance de signaux
reçus, mesurés par la station mobile, pour la pluralité respective de transmissions
de signaux de référence reçus par la station mobile ;
dans lequel le procédé est
caractérisé par :
la réception, par la station de base, du calcul par la station mobile d'au moins un
premier facteur de mérite correspondant (705) basé sur une première relation de la
pluralité de mesures de niveaux de puissance de signaux reçus et une pluralité respective
de niveaux de puissance de transmission ; et
l'octroi, par la station de base, d'une allocation de ressources de transmission de
liaison montante en réponse à celle-ci.
8. Procédé selon la revendication 7, comprenant en outre la réception, par la station
mobile, du calcul d'un deuxième facteur de mérite basé sur une deuxième relation d'au
moins deux facteurs d'une première pluralité de facteurs de mérite, dans lequel l'octroi,
par la station de base, comprend l'octroi d'un paramètre pour une ressource de transmission
de liaison montante vers la station mobile, en réponse à la deuxième relation.
9. Procédé selon la revendication 8, dans lequel le paramètre de transmission de liaison
montante comprend au moins un paramètre parmi (i) le débit de données, (ii) la puissance
de transmission de liaison montante, (iii) le degré ou la nature de la correction
d'erreurs sans voie de retour, (iv) le format de modulation ou (v) l'utilisation de
ressources de code.
10. Procédé selon la revendication 1 ou la revendication 7, dans lequel le système de
communication sans fil est décrit par une Norme Universelle de Télécommunication avec
les Mobiles d'un projet de partenariat de troisième génération, la station de base
est un noeud B, la station mobile est un UE et le noeud B comprend en outre un séquenceur
de liaison montante pour octroyer les paramètres de transmission de liaison montante
à la station mobile dans un MAC-e.
11. Procédé selon la revendication 7, dans lequel le séquenceur de liaison montante estime
le niveau de puissance de signal perturbateur vers une cellule voisine, d'un octroi
hypothétique de ressources de liaison montante avant d'effectuer un octroi de ressources
de liaison montante.
12. Support lisible par ordinateur comportant des instructions exécutables par ordinateur
pour exécuter un procédé d'allocation de ressources de transmission de liaison montante
dans un système de communication sans fil, comprenant :
la réception (703), par une station de base, d'une transmission de données de liaison
montante depuis une station mobile, indiquant la réception, par la station mobile,
d'une pluralité de transmissions de signaux de référence transmis à une pluralité
respective de niveaux de puissance de transmission par une pluralité respective de
stations de base ;
la réception, par la station de base, d'une pluralité de niveaux de puissance de signaux
reçus, mesurés par la station mobile, pour la pluralité respective de transmissions
de signaux de référence reçus par la station mobile ; et
dans lequel le support lisible par ordinateur est
caractérisé par :
la réception, par la station de base, du calcul par la station mobile d'au moins un
premier facteur de mérite correspondant basé sur une première relation de la pluralité
de mesures de niveaux de puissance de signaux reçus et la pluralité respective de
niveaux de puissance de transmission ; et
l'octroi, par la station de base, d'une allocation de ressources de transmission de
liaison montante en réponse à celle-ci.
13. Support lisible par ordinateur selon la revendication 12, comportant des instructions
exécutables par ordinateur pour exécuter un procédé, comprenant en outre la réception,
par la station mobile, du calcul d'un deuxième facteur de mérite basé sur une deuxième
relation d'au moins deux facteurs d'une première pluralité de facteurs de mérite,
dans lequel l'octroi, par la station de base, comprend l'octroi d'un paramètre pour
une ressource de transmission de liaison montante vers la station mobile, en réponse
à la deuxième relation, dans lequel un paramètre de transmission de liaison montante
comprend au moins un paramètre parmi (i) le débit de données, (ii) la puissance de
transmission de liaison montante, (iii) le degré ou la nature de la correction d'erreurs
sans voie de retour, (iv) le format de modulation ou (v) l'utilisation de ressources
de code.
14. Support lisible par ordinateur selon la revendication 13,
dans lequel le système de communication sans fil est décrit par une Norme Universelle
de Télécommunication avec les Mobiles d'un projet de partenariat de troisième génération,
la station de base est un noeud B, la station mobile est un UE et le noeud B comprend
en outre un séquenceur de liaison montante pour octroyer un paramètre pour une ressource
de transmission de liaison montante à la station mobile dans un MAC-e.
15. Support lisible par ordinateur selon la revendication 14,
dans lequel le séquenceur de liaison montante estime le niveau de puissance de signal
perturbateur vers une cellule voisine, d'un octroi hypothétique de ressources de liaison
montante avant d'effectuer un octroi de ressources de liaison montante.
16. Station de base (202) pour un système de communication sans fil, comprenant :
un moyen pour recevoir une transmission de données de liaison montante depuis une
station mobile (201), indiquant la réception, par la station mobile, d'une pluralité
de transmissions de signaux de référence transmis à une pluralité respective de niveaux
de puissance de transmission par une pluralité respective de stations de base ;
un moyen pour recevoir, par la station de base, une pluralité de niveaux de puissance
de signaux reçus, mesurés par la station mobile, pour la pluralité respective de transmissions
de signaux de référence reçus par la station de base ; et
dans lequel la station de base est
caractérisé par :
un moyen pour recevoir, par la station de base, le calcul par la station mobile d'au
moins un premier facteur de mérite correspondant basé sur une première relation de
la pluralité de mesures de niveaux de puissance de signaux reçus et une pluralité
respective de niveaux de puissance de transmission ; et
un moyen pour octroyer, par la station de base, une allocation de ressources de transmission
de liaison montante en réponse à celle-ci.
17. Système de communication sans fil comprenant :
un moyen pour recevoir, par une station mobile, une pluralité de transmissions de
signaux de référence transmise à une pluralité respective de niveaux de puissance
de transmission par une pluralité respective de stations de base ;
un moyen pour mesurer, par la station mobile, une pluralité respective de niveaux
de puissance de signaux reçus correspondant à la pluralité de transmissions de signaux
de référence ;
un moyen pour transmettre, par la station mobile, des informations basées sur la pluralité
de niveaux de puissance de signaux reçus associés à la pluralité respective de transmissions
de signaux de référence ;
dans lequel le système de communication sans fil est
caractérisé par :
un moyen pour recevoir, par une station de base, une transmission de données de liaison
montante depuis la station mobile, indiquant au moins un facteur de mérite déterminé
par la station mobile et basé au moins en partie sur des mesures de niveaux de puissance
de signaux reçus pour une pluralité de transmissions de signaux de référence provenant
d'une pluralité respective de stations de base, mesurés par la station mobile ; et
un moyen pour octroyer, par la station de base, un paramètre de ressources de transmission
de liaison montante à la station mobile, en réponse à l'au moins un facteur de mérite
; et
un moyen pour recevoir, par la station mobile, l'octroi de paramètre de ressources
de transmission de liaison montante.
18. Système de communication sans fil selon la revendication 17, dans lequel le paramètre
de ressource de transmission de liaison montante comprend au moins un paramètre parmi
(i) le débit de données, (ii) la puissance de transmission de liaison montante, (iii)
le degré ou la nature de la correction d'erreurs sans voie de retour, (iv) le format
de modulation ou (v) l'utilisation de ressources de code.
19. Système de communication sans fil selon la revendication 17, dans lequel le système
de communication sans fil est décrit par une Norme Universelle de Télécommunication
avec les Mobiles d'un projet de partenariat de troisième génération, la station de
base est un noeud B, la station mobile est un UE et le noeud B comprend en outre un
séquenceur de liaison montante pour octroyer un paramètre pour une ressource de transmission
de liaison montante à la station mobile dans un MAC-e.
20. Système de communication sans fil selon la revendication 19, comprenant en outre un
moyen par lequel le séquenceur de liaison montante estime le niveau de puissance de
signal perturbateur vers une cellule voisine, d'un octroi hypothétique de ressources
de liaison montante avant d'effectuer un octroi de ressources de liaison montante.